CORRISION STUDIES ON SELF COMPACTING CONCRETE AND COMPARING WITH NORMAL CONCRETE

Abstract

Self-compacting concrete (SCC) can be placed in the form and it can pass through obstructions by its own weight without the need of vibration. It was first developed in Japan in 1988. It gained wider acceptance in Japan, Europe and USA due to its inherent distinct advantages. Although there are visible signs of its gradual acceptance in other countries, Durability is a major concern for concrete structures exposed to aggressive environments. Durability of reinforced concrete structures is influenced by many environmental phenomena. So developing SCC is necessary at this stage in order to increase the durability of the structure. Since then various investigations have been done on this concrete and it is proved that SCC is more durable than normal concrete. Reinforced concrete structures are very durable and capable of withstanding against adverse environmental conditions. However, failures in the structures
do still occur as a result of premature reinforcement corrosion. In the present work different grades of selfcompacting concrete were developed and their flow properties are verified by EFNARC specifications. After getting these mixes compressive strengths are found for these grades and conforming to achieving target strength. Durable property like Sorptivity was studied. The importance of this property is allied to the factor that this is the first phenomenon of transport of aggressive agents that takes place in concrete. Sorptivity, which is an index of moisture transport into unsaturated specimens, has been recognised as an important index. In addition to the above property corrosion studies were also carried. In this research the ability of chloride ions to penetrate in to the concrete must then be known for design as well as quality control purposes. Corrosion is a primary cause of premature deterioration of reinforced concrete which is exposed to dicing chemicals and sea water. Steel reinforcement in concrete is generally protected against
corrosion because of the high alkaline environment of the surrounding cement paste. The cement paste forms a tightly adhering oxide layer over the steel bars and creates a protective environment with a high pH. These studies were carried on potential dynamic polarization studies. After getting the corrosion current, the corrosion rate was also determined.